基于砂岩组构分类评价的储层渗透率预测

Reservoir permeability prediction based on sandstone texture classification

依据以砂岩岩石学特征为基础的不同类型储层孔渗定量关系渗透率预测模型,对川西新场地区上沙溪庙组Js2气藏储层渗透率进行研究。结果表明:研究区储层砂岩以次生孔隙为主,孔渗相关性差,以孔隙度参数进行的储层评价结果与产出状况匹配性差;根据岩石成份、结构和储集空间发育情况对储层进行分类,建立不同类型储层的孔渗定量关系渗透率预测模型,可明显提高孔隙度和渗透率之间的相关性;根据不同类型储层与测井特征的匹配关系,可实现储层类型的测井判别;在提高孔隙度测井解释精度的基础上,利用测井解释孔隙度,分别用不同类型储层的孔渗定量关系渗透率预测模型计算渗透率,可提高渗透率求取精度,从而提高致密砂岩储层渗透率预测水平。

By using different permeability prediction models based on petrologic analysis of the sandstone, the permeability prediction of sandstone was studied for the Upper Shaximiao formation in Xinchang area of Western Sichuan Basin. The re- suits show that the sandstones are secondary porosity dominated with poor porosity-permeability relationships and consequently have a disparity between gas production and reservoir evaluation using porosity data. The reservoirs were classified on the ba- sis of component, texture and pore space types of sandstones, and the corresponding permeability prediction models of porosi- ty-permeability relationship were developed, which can increase the correlation between porosity and permeability. The reser- voir types can be differentiated by analyzing the relationships between reservoir characteristics and well log parameters. Based on enhanced well logging porosity interpretation, more accurate permeability values are obtained by using well-log-calculated porosities and permeability prediction models, which is helpful for improving reservoir evaluation.